Technical Field
The present invention relates to a chemical sensing device, particularly to a chemical sensing device capable of calibrating.
Description of the Related Art
As the breakthrough of the manufacture process of Micro Electro Mechanical System (MEMS) and the miniaturization of the sensing circuit, the MEMS microphone fits the need of the compact size of the modern consumer electronics products, and gradually replaces the traditional electret condenser microphone, and becomes the essential component of the consumer electronics products.
Generally, in order to achieve the high sensitivity of the MEMS microphone thin film, the current MEMS microphone mostly adopts the structure of changing the supporting spring or the MEMS microphone thin film. Taking the structure of changing the supporting spring for example, the method directly controls the coefficient of elasticity of the supporting spring to control the displacement of the MEMS microphone, so that the high voice sensitivity is achieved. For the structure of changing the MEMS microphone thin film, the method directly creates several micro structures on the MEMS microphone thin film for achieving the high voice sensitivity.
Although the aforementioned methods can achieve the high voice sensitivity for the MEMS microphone, but the design is quite complicate. Therefore, there are still rooms for improvement on the design of the MEMS microphone.